Additive for binding agents hardened by hydration and process of forming the same



CAHIWHHZU DAYS ' 16, 1959 G. R. UNDERDOWN 2,890,965 f,- ADDITIVE FOR BINDING AGENTS HARDENED BY HYDRATION 1 ,7 u AND PROCESS OF FORMING THE SAME med Feb. 14. 1955 2 Sheets-Sheet 1 Ca a1, 1150 cam, H20 1 A469), F6203 1 H20 MIX 70 MIX 70 //6 MIX 70 /8 sowr/ow susps/vs/o/v SOLUTION MIX f/G. INTERACT [sow r/ofl I GEL J FPOWDER j I R 3 a E 7'76. 3. 0 aooo 2000- 3 5 E moo- GEORGE R. UNDERDOWN IN I/E N TOR Hue-Mm, ass/11.519,

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June 16, 1959 cs. R. UNDERDOWN 2,890,965

ADDITIVE FOR BINDING AGENTS HARDENED BY HYDRATION AND PROCESS OF FORMING THE SAME 2 Sheets-Sheet 2 Filed F612. 14, 1955 0- m w m w m 03 M $1 @9300 DAYS 40'00 cue/c mnas 0F CONCRETE GEORGE I0,0 OO- UNOERDOW/V United States Patent ADDITIVE FOR BINDING AGENTS HARDENED BY HYDRATION AND PROCESS OF FORMING THE SAME George R. Underdown, Fresno, Calif., assignor of onethird each to Jeannie Underdown and Donald M. Underdown, both of Fresno, Calif.

Application February 14, 1955, Serial No. 488,096

14 Claims. (Cl. 106-89) The present invention relates to binding mediums for aggregate particles, such as sand, gravel, slag, crushed rock, and other organic and inorganic particles, fibres and the like of natural or synthetic origin and more particularly to an additive for such binding agents which when mixed with water form a plastic workable mass and subsequently set or harden by hydration into predetermined form.

The binding agents which harden by hydration include cement, lime, gypsum and the like and are characterized by certain inherent limitations Wellrecognized in the building and allied arts. Such limitations have, of course, not precluded popular use of these binding agents in construction work but have restricted their employment and impaired their full utility.

Solid bodies formed by the hydration of such binding mediums about aggregate particles are not only weakened by shrinkage during curing but frequently by incomplete interspersal of the binding medium about the particles. Asa result of this difiiculty, best construction methods require extensive vibration, compacting, or other mechanical aids to attain the desired intersperal and mass density but even with such expedients, optimum binding is not always attainable.

. Quite generally, the descibed materials either require the initial employment of excess moisture or the supplying of additional moisture, as by spraying, during the curing process. The initial employment of excess water makes handling difiicult and greatly reduces resultant strength. The bleeding of excess moisture during setting makes finishing operations difiicult. Spraying and other modes of providing supplemental water during curing require additional labor and cause extra expense. In many construction situations, these operations are quite difficult or impossible to perform.

Excessive labor requirements are frequently encoungtered in the use of the described binding agents. For ;example, the required vibrating or compacting is frequently an extensive operation.

In the pouring of concrete it is necessary to await the evaporation of surface waters and to permit preliminary setting, after arrangement and compacting or vibrating the concrete in position, before finishing the surface thereof. It is thus frequently necessary, to have expensive laborers wait for protracted periods until the particular weather and other environmental conditions permit surfacing and, even at such time, it is the usual practice to add a surface layer of pure cement to make finishing troweling practical.

The described materials gain strength quite slowly, being regarded as assuming a preliminary set in approximately three days and a final set in twenty-eight days. It is also known that they sometimes sufifer strength retrogression at various times after the twenty-eighth day rather than continued strength increase incident to proper curing. Additives are known for speeding the hardening process but generally speaking they are expensive or difficult to employ and thus are limited in their application.

A further known disadvantage encountered in environ- 2,890,965 Patented June 16, 1959 ments involving elevated temperatures is that the materials expand during hardening making size control impossible. While this difficulty is not generally encountered, it is typified by the utilization of concrete in oil wells where the elevated temperatures frequently cause such expansion as to make concrete use a most unsatisfactory operation.

Additionally, in order to overcome one or more of the described difiiculties, building codes, architectural and engineering specifications, and other controls frequently require the employment of excessive quantities of binding agents. Inasmuch as the binding agent contents of the aggregate mixes are a direct function of the cost thereof, the aggregates being comparatively inexpensive, the eventual product is frequently excessive increased in cost in order to attain desired strengths standards and safety factors.

An object of the present invention is, therefor, to provide an additive for binding mediums of the character described conducive to the improved performance of their binding functions.

Another object is to minimize or eliminate volume and linear change in cement, concrete, plaster, mortar and the like incident to hydration.

Another object is to minimize or eliminate cracking of cement, concrete, plaster, mortar and the like during hardening.

Another object is to make possible accurate size control in aggregates bound into a solidified whole by hydrated binding materials of the character described.

Another object is to provide cementitious materials of improved plasticity and flowability for form fillingpur; poses from which the forms may promptly be removed after filling.

Another object is to provide an additive for cement and concrete adapted to condition said cement and concrete for immediate surface finishing upon emplacement thereof.

Another object is to increase the hardened strength of cement, concrete, plaster, mortar and like binding agents.

Another object is to provide an additive which imparts to binding material of the character described a measure of water-proofing and resistane t erosion, cavi -u ne y water and other liqui Another object is to provide an additive for the binding agents hardened by hydration capable of incorporating adequate curing moisture for the binding agents without incurring initial bleeding of excess moisture therefrom so as to permit prompt surface finishing and/or the avoiding of subsequent spraying or other supplementing of curing moisture.

Another object is substantially to reduce the labor costs incident to construction involving cement, concrete, plaster, mortar and the like.

A further object is to provide an additive for binding agents hardened by hydration adapted to render the early strength of such agents dependably predictable and to avoid strength retrogression subsequent to curing as is sometimes conventionally encountered.

Still further objects and advantages will become apparent in the subsequent description in the specification.

In the drawings:

Fig. 1 is a fiow diagram illustrating a method of forma tion of the additive of the present invention.

Fig. 2 is a graph showing relative compression strengths of a conventional standard cement as compared with the same cement containing different quantities of the additive of the present invention.

Fig. 3 is a graph showing relative compression strengths of a conventional standard cement of high early strength as compared with the same cement containing a defined quantity of the additive of the present invention.

Fig. 4 is a graph illustrating shavings in cement per cubic yard of concrete made possible by the practice of the present invention without impairing strength or durability.

Referring in greater particularity to the drawings:

In Fig. 1, the first steps in forming the additive of the present invention are illustrated to be the separate formation of an aqueous calcium chloride solution, an aqueous calcium carbonate suspension and an aqueous aluminum sulfate solution. For illustrative convenience, a source of calcium chloride is illustrated at 10, a calcium carbonate source at 11, an aluminum sulfate source at 12, a red iron oxide source at 13 and water sources at 14. Calcium chloride is mixed with water 14 to form a solution. This action is exothermic, the heat generated preferably being permitted to dissipate prior to employment of the solution.

The calcium carbonate 11 in finely divided form is mixed with water 14 to form an aqueous suspension.

Aluminum sulfate 12 is dissolved in water 14 to form an aqueous solution. This action is also exothermic and the heat generated preferably dissipated prior to use of the solution. Red iron oxide 13 is added to the water with the aluminum su ate and although it does not appear to enter into the chemical activity of the aluminum sulfate and is optionally employed, it is of substantial advantage in the additive. In many locations, the described solutions and suspension may be conveniently available without their formation in the manufacturing process. In such instance, the relative quantities of the chemicals employed in the water should be regulated to approximate the proportions subsequently described.

The calcium chloride solution 15 is then mixed with the calcium carbonate suspension 16 to form an aqueous mixture shown at 17. Apparently there is no chemical activity incident to this intermixing but the formation of the mixture at 17 prior to interaction with the aluminum sulfate solution 18 is essential to fully successful practice of the present invention. The alu to solution 18 containing the iron oxide 13 is then added to the ,calcipm chloride and calcium c rbonate mixture 17. mough intlma e adr n ixtum, stirring at this point, for reasons not fully apparent, is fatal to the formation of the additive of the present invention in its fully effective form. The desired intermixing is attained in commercial production by discharging the aluminum sulfate solution 18 vigorously into the mixture 17 and thereafter avoiding all stirring action while the following reaction is concluded.

When the aluminum sulfate solution 18 is interacted with the mixture 17, as illustrated at 19, the chemical activity is vigorous and pronounced. The material bubbles vigorously and discharges a gas believed to be carbon dioxide and perhaps chlorine. Although heat is released, it is much less than the vigor of the action would normally suggest. Promptly after interaction of the aluminum sulfate solution 18 and the calcium chloride and calcium carbonate mixture 17, the resultant material substantially quadruples in volume while appearing to boil violently. Promptly upon reaching approximately quadruple volume it settles to about double volume. Thereupon it again rises to quadruple volume and again settles to about double volume. When the admixture is properly performed, the material expands a third time, but in this instance to approximately triple volume, and then again sinks to approximately double volume. Finally, there is a fourth detectable increase in volume, although it is slight, whereupon the material sinks to approximately one and one-half times its initial volume. This vigorous surging and receding, all accompanied by pro nounced bubbling action, occurs in approximately six seconds. There is an audible hissing sound emitted apparently incident to the release of gas as a gelatinous precipitate is formed. At the end of approximately 10 minutes, a past-like precipitate is established which contains a multitude of small pockets of gas.

From approximately ten minutes to an hour after the aluminum sulfate solution is added, the precipitate which is formed at 19 is expressed by stirring, pressing or the like to release the entrapped gas. The material is then ready for use or storage in its paste form, as at 20, for dissolving in aqueous solution at 21 for use or storage, or dehydration and grinding into powder form, as represented at 22.

Before proceeding to a description of the preferred proportions of the ingredients, it should be observed that the interaction at 19 must be carefully performed. Not only must stirring be avoided but for some reason not known to the applicant, if the intermixed liquids at 19 are too shallow during the interacting period, the results are seriously impaired. For example, a 9-inch fluid depth is excellently suited to the purpose but a 3-inch depth results in incomplete interaction and comparable decrease in effectiveness of the resultant product. This may possibly be due to the gentle mixing effect of the release of carbon dioxide in the deeper liquids.

In each instance, the solutions at 15 and 18 preferably contain at least about twice as much water by weight as their solutes. Generally, the suspension 16 preferably contains at least about twice as much water by weight as the calcium carbonate employed. When excess water is employed, it fails to enter into the chemical activity resulting in the gelatinous precipitate and floats on top making precise measurement of water needed for subsequent hydration of the binding agents difficult to calculate. When appreciably less water than that prescribed is utilized, chemical activity and material formation is impaired. It is noted that both increasing and decreasing the amount of water employed causes crystallization rather than formation of the gelatinous precipitate and precludes the attainment of the full advantages described. The relative proportions of the calcium chloride, calcium carbonate, aluminum sulfate and iron oxide may vary considerably and preferably are determined in accordance with different uses, as will subsequently be described.

However it should not be inferred that the calcium chloride, calcium carbonate and aluminum sulfate act independently and without cooperative eflect. Although the precise chemical activity at 19 and the chemical action on binding agents requiring hydration are not fully understood and cannot be confirmed without extensive research, the calcium chloride, calcium carbonate, and aluminum sulfate attain results when employed cooperatively that are not attainable by their alternate or successive utilization. It is thought that the iron oxide does not enter into the action but continues in the material in an uncombined condition. Incorporating it into the aluminum sulfate solution in the manner described is the only successful manner known to the applicant. Mixing it with the calcium carbonate suspension, the final gel, or even with the binding agents prior or subsequent to mixing with the additive does not attain the full advantages of its introduction with the aluminum sulfate solution. Of less significance but of ready demonstration, the light red coloring of the iron oxide is desirable. If it is introduced with the calcium chloride or calcium carbonate, it loses its color properties during the interaction at 17 but when introduced with the aluminum sulfate, the full coloring effect results. It is believed that in cement the iron oxide combines with tricalcium aluminate to form tetracalcium alumino-ferrite. This property of iron oxide has been known but its introduction in the additive in the manner described achieves markedly superior results.

It is readily demonstrated that cooperative employment of the described ingredients is required to attain the advantages of the present invention. Aluminum sulfate is known as an inorganic salt which actively attacks concrete, plaster, mortar and the like. Heretofore effort has been made to combat its effect on-such materials when the materials are located in environments where aluminum sulfate may be encountered. It clearly cannot be used alone without disasterous efiects. Similarly, calcium chloride is known to attack such materials, although with somewhat less vigor. It thus cannot be employed alone. Obviously, the calium carbonate employed alone is of no significant effect. Further, if the calcium carbonate and aluminum sulfate are mixed and added to thehydrating bindingagents, no advantage is attainecLand it is subsequently impossible to introduce" the calcium chloride to the mixture and achieve any desired chemical interaction. In this connection it is of interest to observe that if calcium chloride is added to a mixture of such a binding agent and the additive of the present invention, the activity of the additive is immediately terminated and its beneficial efiects lost. The utilization of calcium carbonate with aluminum sulfate in the absence of calcium chloride, determined experimentally, results in no strength increase of binding agents as a result thereof although there is some noticeable improvement in workability and the heat of hydration appears to be somewhat reduced. WhflLlbLcalcium chloride is employed with aluminum sulfate without calcium caLhQ E i n atifactory product also results. Emm u-ssi2i fii'l .E lsat mass is formed notf NW Reference is now made by way of illustration rather than limitation to various successful proportions of the ingredients of the present invention, as follows:

Example 1 The most popular form of the additive of the present invention employs the following proportions of ingredients: 1 part by weight calcium chloride vl part by weight calcium carbonate 1 part by weight aluminum sulfate As described, the calcium chloride and aluminum sulfate are separately dissolved in water in quantities equal to substantially twice their respective weights. The calcium carbonate is mixed with substantially twice the The amount of water by weight to form a suspension. calcium carbonate suspension and calcium chloride solution are mixed and the resultant mixture interacted with the aluminum sulfate solution to form the gelatinous precipitate.

Example 2 The additive of the present invention best suited to,

Modified Portland Cement Type II, as known in the tradefii is formed from approximately: Ml

2 parts by weight calcium chloride 2 parts by weight calcium carbonate 1 part by weight aluminum sulfate The material is formed in the manner described with respect to Example 1 with the calcium chloride and the aluminum sulfate being dissolved, and the calcium carbonate being suspended, separately in quantities of Water of substantially their respective weights. This additive attains extremely early strength and is employed with the defined binding agents where such early strength is of particular importance.

2 parts by weight calcium carbonate 3 parts by weight aluminum sulfate As before, each ingredient is employed with approximately twice its weight of water and the material formed in the manner previously described.

Example 4 In situations in which high ultimate strength is a particular objective, the following is excellently suited to the purpose:

1 part by weight calcium chloride 1 part by weight calcium carbonate, 2 parts by weight aluminum sulfate Similarly, each of the listed ingredients is employed with substantially twice its weight of water in the process described to form the additive.

Example 5 For gypsum plasters and the like, the additive is preferably formed from:

1 part by weight calcium chloride 4 parts by weight [calcium carbonatg 6 parts by weight aluminum sulfate Like the preceding examples, each of the listed ingredients is employed with substantially twice its weight of water and the decribed process followed to form the gelatinous precipitate. The maximum proportion of calcium chloride permitted by gypsum is much lower than for lime or cement and thus for gypsum plaster relatively less calcium chloride is employed as compared with the calcium carbonate and the aluminum sulfate. e

fixample 6. For lime plaster and lime mortar the additive pref- 5 erably utilizes:

1 part by weight calcium chloride 2 parts by weight calcium carbonate 3 parts by weight aluminum sulfate/ 0 three ingredients are employed. Further reduction. still results in improved workability and plasticity of concrete, plaster, mortar and the like but the full strength advantages, size control, and avoidance of shrinkagecracking are lost. For normal uses, the maximum proportions of calcium carbonate and aluminum sulfate relative to the calcium chloride are demonstrated by Example 5. Further increase results in too rapid setting for most uses and makes proper form filling and finishing difficult.

In all of the foregoing examples, iron oxide is preferably employed in the aluminum sulfate solution and although the quantity of the iron oxide may be varied considerably it is most advantageously employed in an amount equal to approximately one-eighth of the aluminum sulfate utilized.

The gel 20 may be used directly as an additive for the mixing water for binding agents hardened by hydration or stored in that form. Further, the gel may be used or stored in aqueous solution. Where it is necessary to transport the additive substantial distances or under- 70 difficult conditions and/or for protracted storing, the gel is preferably not only dehydrated but subjected to burning action at a temperature of approximately 2500 F. Such burning appears further to improve the strength improving properties of the additive. The material is 75 then powdered for ease in subsequent dissolving and in the powder form weighs approximately one-third of its weight in paste form.

The advantages of the burning or oxidation of the additive of the present invention are conveniently obtained in commercial practice by adding the gelatinous precipitate 20 to the slurry formed of the argillaceous and calcareous materials prior to their heating to fusion in the cement plant. In this way, the precipitate is dehydrated and oxidized concurrently with the heat treating of the cement materials and upon pulverization of the resultant clinkers the dry powdered cement is found to contain the oxidized additive in whatever predetermined proportion is desired.

In utilizing the additive with the described binding agents, it is important that the additive be present as soon as the dehydration commences or only part of the advantages of the additive are enjoyed. The additive, in solution, paste, or powder, is normally mixed with the water of hydration which is added to such binding agents prior to the mixing of the binding agents and their aggregates. In the dissolving of the additive with the water of hydration, care is observed to make certain that the additive is held in solution.

It is also practical to mix the powdered form of the additive with dry binding agents of the character described so that when water is added for hydration purposes, the powder promptly dissolves and is present in the resultant mixture during hydration. Commercially this is a convenient expedient inasmuch as no special handling of the additive is required by the customer. This convenience also results from oxidation of the additive during the cement burning process in the cement plant.

The additive of Example 1 is preferably employed with standard Portland cement in forming concrete or the like. If the paste or solution is employed, it is preferably placed in the mixture with the measured quantity of water required by the concrete. For each sack of standard cement employed, not less than 4 /2 lbs. of the additive in paste form, or its equivalent, should be employed and as much as 18 lbs. per sack of cement may be utilized with even furtherimproved results. As will subsequently be apparent, the utilization of approximately 9 lbs. of the paste for each sack of cement approximately doubles the strength of the resultant product, and attains a far superior workability. When the additive is thoroughly dissolved in the water, the binding agent and aggregate, preferably previously dry mixed, are added. It has been noted that if the additive is introduced after the cement has become thoroughly dampened by the water, the increased strength is not attained although improved working characteristics are still noticeable.

Similarly, in the formation of gypsum plasters, the additive is first dissolved in the water required for subsequent hydration purposes, in this instance the additive of Example is preferably employed. Subsequently the mixed gypsum and sand are mixed in the usual way with the treated water and the plaster handled in the normal manner. The gypsum plaster so treated avoids or minimizes the release of heat by hydration and thus the cracking and shrinking incident thereto. Further, it is adhesive to materials such as glass and the like to which normal plaster cannot be caused to adhere. The gypsum plaster after setting is of substantially twice the compressive strength of normal gypsum plaster of the same formulation when 4% lbs. of the additive are employed for each 100 lbs. of gypsum. Further, the resultant product prior to hardening is much easier to work and surface finishing is more quickly and economically completed and better results made possible.

In the same manner improved workability, plasticity, hardening strength and crack resistance are attained in lime plaster and mortar by the addition of the additive in the manner described.

From the foregoing, it will be readily understood that the additive of the present invention is advantageously utilized with the described binding agents to improve their binding characteristics for aggregates previously employed therewith and that the binding characteristics are so improved that the agents may be utilized with aggregate materials heretofore regarded as impractical to incorporate in the binding agents.

Of perhaps the greatest advantage is that concrete, plaster and mortar employing the additive in the manners described are far more plastic and flowable than normal and thus more readily fill forms, lath apertures and the like therefor. Further, such materials are given a vastly improved troweling surface paste, referred to in the trade as fatness. Approximately 6 as much vibrating or compacting is required and no delay is needed once such materials are deposited before finishing can be started. This is particularly significant in concrete work in which an average saving of 36% in labor required to position and finish the concrete is made.

While the instant invention is described in terms of particular ingredients, and ranges thereof, to be used, it is obvious that many modifications and variations in the proportions of the ingredients may be made without departing from the spirit and scope of the invention, and only such limitations should be imposed as are indicated in the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A composition of matter for use in cement, concrete, plaster, mortar and the like which is adapted to improve the workability and resultant strength thereof comprising the product of approximately one part by weight of calcium chloride dissolved in two parts of water intermixed with approximately one to .four parts of finely divided calcium carbonate suspended in from two to eight parts of water with the calcium carbonate of the resultant mixture interacted in the presence of the calcium chloride solution with approximately one to six parts of aluminum sulfate dissolved in from two to twelve parts of water.

2. The composition of claim 1 in which about part by weight of iron oxide is mixed with the aluminum sulfate solution prior to its interaction with the calcium carbonate of the intermixed calcium chloride solution and calcium carbonate suspension.

3. A composition of matter comprising a reaction product of an aqueous calcium chloride solution intermixed with calcium carbonate in aqueous suspension with the calcium carbonate subsequently being interacted with an aqueous aluminum sulfate solution in the presence of the calcium chloride solution, the quantities of water in the aqueous solutions and suspension being approximately twice the weights of the calcium chloride, calcium carbonate and aluminum sulfate respectively therein and approximately one part by weight of calcium chloride, approximately from 1 to 4 parts by weight calcium carbonate, and approximately from 1 to 6 parts by weight aluminum sulfate being employed.

4. A composition of matter comprising a reaction product of an aqueous calcium chloride solution intermixed with calcium carbonate in aqueous suspension with the calcium carbonate subsequently being interacted in the presence of the calcium chloride solution with an aqueous aluminum sulfate solution containing iron oxide in suspension, the quantities of water in the aqueous solutions and suspension being approximately twice the weights of the calcium chloride, calcium carbonate and aluminum sulfate respectively therein, and approximately one part by weight of calcium chloride, approximately from 1 to 4 parts by weight calcium carbonate, approximately from 1 to 6 parts by weight aluminum sulfate, and approximately one-eighth part by weight of iron oxide being employed.

5. A cementitious material containing Portland cement and an additive, the additive being present in approximately 4.5% to 18% by weight of the cement, the additive comprising the product of an aqueous mixture of approximately one part by weight of calcium chloride in solution in the water of the mixture and approximately 1 to 4 parts by weight of finely divided calcium carbonate suspended in the water of the mixture interacted in the presence of the calcium chloride solution with approximately 1 to 6 parts by weight of aluminum sulfate in aqueous solution.

6. A cementitious material containing Portland cement and an additive adapted to improve workability and ultimate strength of the material, the additive being present in approximately 4.5 to 18% by weight of the cement, the additive comprising the product of approximately one part by weight of calcium chloride dissolved in two parts of water intermixed with approximately 1 to 4 parts of finely divided calcium carbonate suspended in from 2 to 8 parts of water with the calcium carbonate of the resultant mixture interacted in the presence of the calcium chloride solution with approximately 1 to 6 parts of aluminum sulfate dissolved in from 2 to 12 parts of water.

7. A method of producing an additive for cement, concrete, plaster, mortar and the like comprising intermixing an aqueous calcium chloride solution with an aqueous calcium carbonate suspension to form a substantially homogeneous mixture, and subsequently interacting the calcium carbonate of the resultant mixture with aqueous aluminum sulfate solution whereby vigorous chemical activity is evident and aluminum hydroxide as a gelatinous precipitate formed, the water content of the calcium chloride solution, calcium carbonate suspension, and aluminum sulfate solution being insufiicient to permit said chemical action to proceed to completion, the calcium carbonate being utilized in from approximately 1 to 4 times the weight of the calcium chloride employed and the aluminum sulfate being utilized in from approximately 1 to 6 times the weight of said calcium chloride.

8. A method of producing an additive for cement, concrete, plaster, mortar and the like requiring hydration for solidifying purposes comprising intermixing an aqueous calcium chloride solution with an aqueous calcium carbonate suspension to form a substantially homogeneous mixture, and subsequently interacting the calcium carbonate in the resultant mixture with an aqueous aluminum sulfate solution in the absence of external agitation to form aluminum hydroxide as a gelatinous precipitate, approximately one part by weight of the calcium chloride, approximately one to four parts by weight of the calcium carbonate, and approximately one to six parts by weight of the aluminum sulfate being employed.

9. A method of producing an additive for cement, concrete, plaster, mortar and the like requiring hydration for solidifying purposes comprising forming a solution of approximately one part by weight of calcium chloride in approximately two parts by weight of water, forming a suspension of approximately one part by weight of finely divided calcium carbonate in approximately two parts by weight of water, intermixing said solution and suspension, and subsequently mixing the resulting mixture with a solution of approximately one part by weight of aluminum sulfate with approximately two parts by weight of water whereby the calcium carbonate interacts with the aluminum sulfate to form aluminum hydroxide as a gelatinous precipitate holding the calcium chloride and other products of the interaction.

10. A method of producing a composition of matter for use as an additive for binding agents hardened by hydration comprising dissolving approximately one part by weight of calcium chloride in water, mixing approximately one to four parts by weight of finely divided calcium carbonate with water to form a suspension thereof, dissolving approximately one to six parts by weight of aluminum sulfate in water, mixing the calcium chloride solution and the calcium carbonate suspension, and subsequently mixing the calcium chloride and calcium carbonate aqueous mixture with the aluminum sulfate solution whereby the calcium carbonate interacts with the aluminum sulfate in the presence of the calcium chloride to form aluminum hydroxide, calcium bicarbonate and calcium sulfate.

11. A process for forming an additive for cement, concrete, plaster, mortar and the like comprising forming an aqueous solution of calcium chloride, forming an aqueous suspension of finely divided calcium carbonate, forming an aqueous solution of aluminum sulfate, forming a suspension of iron oxide in the aluminum sulfate solution, approximately one part by weight of calcium chloride, one to four parts by weight of calcium carbonate, one to six parts by weight of aluminum sulfate and one-eighth part by weight of red iron oxide being employed, mixing the calcium chloride solution and the calcium carbonate suspension, and subsequently mixing the mixture of the calcium chloride solution and calcium carbonate suspension with the aluminum sulfate solution containing the iron oxide in suspension whereby the calcium carbonate and aluminum sulfate interact in the presence of the calcium chloride to form aluminum hydroxide as a gelatinous precipitate containing the noninteracted calcium chloride and the other products of the interaction.

12. A process for forming an additive for cement, concrete, plaster, mortar and the like comprising dissolving approximately one part by Weight of calcium chloride in 2 parts by weight of water, forming a suspension of approximately one to 4 parts by weight of calcium carbonate in from 2 to 8 parts of water respectively, dissolving approximately one to 6 parts by weight of aluminum sulfate in from 2 to 12 parts of water respectively, mixing the calcium chloride solution and the calcium carbonate suspension, and subsequently mixing the aqueous calcium chloride and calcium carbonate mixture with the aluminum sulfate solution whereby an exothermic reaction occurs and a gelatinous precipitate in the form of aluminum hydroxide is produced by the interaction of the aluminum sulfate and the calcium carbonate.

13. In a method of producing a water soluble composition of matter for use as an additive in aqueous solution for cement, concrete, plaster, mortar and the like requiring hydration for hardening purposes, forming a solution of at least about one part by weight of calcium chloride in 2 parts by weight of water, forming a suspension of at least about one to 4 parts by weight of finely divided calcium carbonate in from 2 to 8 parts of water respectively, forming a solution of at least about one to 6 parts by weight of aluminum sulfate in from 2 to 12 parts of water respectively, mixing the calcium chloride solution and the calcium carbonate suspension subsequently, mixing the aqueous calcium chloride and calcium carbonate mixture with the aluminum sulfate solution whereby an exothermic reaction occurs releasing carbon dioxide and forming aluminum hydroxide as a gelatinous precipitate, after release of the carbon dioxide expressing bubbles of carbon dioxide entrapped in the precipitate, and dehydrating the precipitate to form a substantially stable anhydrous product.

14. The process of claim 13 in which at least about A; part by weight of red iron oxide is mixed with the aluminum sulfate solution prior to mixing said aluminum sulfate solution with the aqueous calcium chloride and calcium carbonate mixture.

(References on following page) 11 12 References Cited in the file of this patent 2,336,723 Drummond Dec. 14, 1943 UNITED STATES PATENTS 2,553,613 Wilson M y 95 334 g i i gf 3g FOREIGN PATENTS a e c- 1,402,133 Ashenhurst 1m 3, 1922 5 8 Great Bn m ep 2, 1926 1,604,169 Johnston et a1 Oct. 26, 1926 1,863,663 Lauderman June 21, 1932 OTHER REFERENCES 7 455 Hirschman J l 25 1939 Page 262 of publication entitled National Paint Dic- 2,220,667 Travis Nov. 5, 1940 10 fionary, y Stewart edition), 9 

1. A COMPOSITION OF MATTER FOR USE IN CEMENT, CONCRETE, PLASTER, MORTAR AND THE LIKE WHICH IS ADAPTED TO IMPROVE THE WORKABILITY AND RESULTANT STRENGTH THEREOF COMPRISING THE PRODUCT OF APPROXIMATELY ONE PART BY WEIGHT OF CALCIUM CHLORIDE DISSOLVED IN TWO PARTS OF WATER INTERMIXED WITH APPROXIMATELY ONE TO FOUR PARTS OF FINELY DIVIDED CALCIUM CARBONATE SUSPENDED IN FROM TWO TO EIGHT PARTS OF WATER WITH THE CALCIUM CARBONATE OF THE RESULTANT MIXTURE INTERACTED IN THE PRESENCE OF THE CALCIUM CHLORIDE SOLUTION WITH APPROXIMATELY ONE TO SIX PARTS OF ALUMINUM SULFATE DISSOLVED IN FROM TWO TO TWELVE PARTS OF WATER. 